Calling cards were first invented in the mid 1970's in Europe as a way to pay for phone calls upfront allowing calls to be made from phone booths without using change. A calling card is a pre-paid card that allows a purchaser to purchase phone call minutes upfront and later redeem those minutes for use at a later time. Calling cards were first only available for making local calls. The cards were similar to a credit card in having a magnetic strip on the card which encoded the balance available on the calling card.
During the 1980's calling cards became available in the United States to make international phone calls. International calling cards enable a buyer to purchase a card with usage rates, which are country specific.
A SMS or short message service is a text message that is usually sent from one mobile handset to another. However, other mobile devices also support the SMS format as a communication tool. SMS text allows a person to send a short message to a recipient in a short amount of time. Recently, the usage of SMS has become wide spread as a communication tool.
Calling card technology has evolved from its early days of requiring a customer to purchase a calling card and use the card itself to use the calling card minutes purchased. However, calling card minutes could be easily completely lost if the physical card itself was lost.